SOA concepts in Web Services Journal

The Web Services Journal also covers XML and Service-Oriented Architecture.

The website at webservices.sys-con.com is so incredibly busy, with things scattered all over the place, that it would be a good candidate for the World Usability Day hall of shame.

With enough determination and luck, you can eventually discover that digital editions of the Sys Con magazines are available for free online, in both Flash and PDF format, at www.sys-con.com/general/digitaleditions.htm

In the Web Services Journal September 2005 issue (PDF), Thomas Erl has an article "The Principles of Service-Orientation" in which he does a good job of extracting the core concepts of SOA from all the vendor and Web Services noise.